<html>
<head>
<title>Pelican preflight wizard</title>
</head>
<body onload="disableNext()">

<h1>Eyes</h1>

<hr/>
<form id="checklist">
<ol>
<li>Warn anyone else in the arena that you're about to take off. <input type="checkbox" id="warn" onclick="enableNext()" /></li>
<li>Put goggles on.  Make sure everyone else present has goggles on. <input type="checkbox" id="goggles" onclick="enableNext()" /></li>
<li>Look around the arena for excessive spectators or people about to walk in. <input type="checkbox" id="crowd" onclick="enableNext()" /></li>
</ol>
</form>
<hr/>

<form id="nav">
<button type = "button" onClick="window.location.href='ros.html'">Previous</button>
<button id="btn_nxt" type = "button" onClick="window.location.href='fly.html'">Next</button>
<button type = "button" onClick="window.location.href='start.html'">Cancel</button>
</form>

<script>
function disableNext() {
    document.getElementById("btn_nxt").disabled = true;
}
</script>

<script>
function enableNext() {

if (document.getElementById("warn").checked) {
if (document.getElementById("goggles").checked) {
if (document.getElementById("crowd").checked) {
  document.getElementById("btn_nxt").disabled = false;
}
}
}

}
</script>

</body>
